all butter puff pastry (if you make your own I'm impressed beyond words...)

a beaten egg

Remove any giblets or string, then put chicken in a big pot. Cover with chicken stock, add roughly chopped carrots for extra kudos, put lid on and bring to boil. Simmer for 45 minutes.

Take chicken out, leave to cool. While it's cooling bring the stock back up to a high temperature and leave on a rolling boil until reduced in volume by half.

Meanwhile, when your chicken is cool enough not to burn your fingers - strip all the meat off the carcass. Cut into medium pieces, put aside the skin and bones just in case you have energy to make more stock later.

Then fry your leek and onion in butter until soft (5 ish minutes on medium heat)

At the same time fry your button mushrooms separately on a high heat in butter. When browned give them a good few grinds of pepper. Put them together with the leeks and onions.

Right, now your stock should have finished reducing.

Take another pan (your washing up sink will be pretty full by now...) and melt more butter. Fry the flour for a couple of minutes.

Then add the reduced stock a ladle at a time until you have a hot, thick, creamy looking sauce.

Get the consistency right (if it's too thin leave it to reduce a bit again) and then add the chopped parsley and a good slug of cream. Then fold in the vegetables and the chicken and give it a good grind of pepper and a squeeze of lemon juice.

By this point this should smell fantastically chickeny and you'll probably be hungry to lick the pan out. So pour the mixture into your favourite pie dish, top with pastry (remember to poke a few holes in it), brush with beaten egg and then cook in a 180º C oven for 25 minutes until the pastry is golden brown.